text: #    Copyright 2014-2015 ARM Limited
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  #
  # pylint: disable=attribute-defined-outside-init
  import wlauto.core.signal as signal
  from wlauto import Module
  from wlauto.exceptions import DeviceError
  
  
  class CpuidleState(object):
  
      @property
      def usage(self):
          return self.get('usage')
  
      @property
      def time(self):
          return self.get('time')
  
      @property
      def disable(self):
          return self.get('disable')
  
      @disable.setter
      def disable(self, value):
          self.set('disable', value)
  
      @property
      def ordinal(self):
          i = len(self.id)
          while self.id[i - 1].isdigit():
              i -= 1
              if not i:
                  raise ValueError('invalid idle state name: "{}"'.format(self.id))
          return int(self.id[i:])
  
      def __init__(self, device, path):
          self.device = device
          self.path = path
          self.id = self.device.path.basename(self.path)
          self.cpu = self.device.path.basename(self.device.path.dirname(path))
          self.desc = self.get('desc')
          self.name = self.get('name')
          self.latency = self.get('latency')
          self.power = self.get('power')
  
      def get(self, prop):
          property_path = self.device.path.join(self.path, prop)
          return self.device.get_sysfile_value(property_path)
  
      def set(self, prop, value):
          property_path = self.device.path.join(self.path, prop)
          self.device.set_sysfile_value(property_path, value)
  
      def __eq__(self, other):
          if isinstance(other, CpuidleState):
              return (self.name == other.name) and (self.desc == other.desc)
          elif isinstance(other, basestring):
              return (self.name == other) or (self.desc == other)
          else:
              return False
  
      def __ne__(self, other):
          return not self.__eq__(other)
  
  
  class Cpuidle(Module):
  
      name = 'cpuidle'
      description = """
      Adds cpuidle state query and manupution APIs to a Device interface.
  
      """
      capabilities = ['cpuidle']
  
      root_path = '/sys/devices/system/cpu/cpuidle'
  
      def probe(self, device):
          return device.file_exists(self.root_path)
  
      def initialize(self, context):
          self.device = self.root_owner
          signal.connect(self._on_device_init, signal.RUN_INIT, priority=1)
  
      def get_cpuidle_driver(self):
          return self.device.get_sysfile_value(self.device.path.join(self.root_path, 'current_driver')).strip()
  
      def get_cpuidle_governor(self):
          return self.device.get_sysfile_value(self.device.path.join(self.root_path, 'current_governor_ro')).strip()
  
      def get_cpuidle_states(self, cpu=0):
          if isinstance(cpu, int):
              cpu = 'cpu{}'.format(cpu)
          states_dir = self.device.path.join(self.device.path.dirname(self.root_path), cpu, 'cpuidle')
          idle_states = []
          for state in self.device.listdir(states_dir):
              if state.startswith('state'):
                  idle_states.append(CpuidleState(self.device, self.device.path.join(states_dir, state)))
          return idle_states
  
      def _on_device_init(self, context):  # pylint: disable=unused-argument
          if not self.device.file_exists(self.root_path):
              raise DeviceError('Device kernel does not appear to have cpuidle enabled.')
  
  